The invention relates to equipment for pretreatment of a catalyst and/or for micropilot-type catalytic testing that make it possible to establish the material balance of a chemical reaction in the presence of very small amounts of solid catalyst. It also relates to a process for pretreatment of catalysts and/or catalytic testing that is implemented in the equipment according to the invention.
The invention also relates to the use of the equipment according to the invention to solve problems that are associated with the use of catalysts in the areas of refining, petrochemistry, treatment or conversion of gas, or fine chemistry.
The evaluation of the performances of new solids in heterogeneous catalysis in reactions for converting liquid feedstocks in the presence of gaseous reagents should be carried out under a wide range of experimental conditions (pressure, flow rates, temperature, concentrations of reagents). The length of time that it takes to carry out the complete testing of a solid depends on, on the one hand, the dwell time of the reagents in contact with the catalyst, and, on the other, run-up times between each modification of the value of an experimental parameter.
The measurements of catalytic activity on a laboratory scale are frequently made in the gaseous phase on model substances that represent reactions under study. The study of the activity of small amounts of catalysts in the presence of industrial feedstocks that comprise at least one liquid product is generally done only in a batch reactor (autoclave). Very often, the amount of catalyst that is needed to carry out a test on a pilot unit which usually uses a catalyst volume of 20 to 1000 cm3 and whose reactor has a volume that is generally greater than 50 cm3 is not available.
The design of the small pilot installations (micropilot-type equipment) that are intended for the evaluation of the performance of new catalytic formulations in the conversion of liquid feedstocks relies on the miniaturization of industrial pilot units. The equipment generally comprises reactors that can hold several cubic centimeters of catalyst. The flows of reagents, liquid feedstock, and reactive gas are regulated with elements such as metering pumps and regulating valves. The separators that ensure the distribution of gaseous and liquid effluents are based on, as for the pilot units, the regulation of a liquid level. The order of magnitude of the dwell time of the feedstock in the reactor can be very high since the reactivity of the feedstock is low or the harshness of the treatment is increased. Thus, the hourly volumetric flow rates on the order of 2 hxe2x88x921 are commonly used. Such values, compared to the volumes of the reactors and systems for separation and collection, consequently have run-up times on the order of several days. The evaluation of the activity of a catalyst should cover a wide range of reaction conditions, which involves frequent variation of the operating parameters of the reactor (pressure, flow rates, temperature). A long regulating period after each modification of the value of one of these magnitudes severely penalizes the productivity of such an installation.
The applicant, who is confronted with the need for carrying out a number of catalytic activity tests under conditions that are identical to those of the industrial reactors, developed micropilot-type equipment and a process for testing and collecting samples for analysis that make it possible to obtain a quick response to each evaluation experiment. This purpose of the equipment and of the process according to the invention is achieved by a reduction of the run-up times that are associated with the small sizes and with the very small amount of catalyst, as well as by forced automation, compared to the pilots and test processes that are mentioned above. The equipment and the process according to the invention thus make it possible to collect samples of liquid or gaseous effluents that are separated after reaction for the purposes of complementary analyses, if necessary, unlike the equipment that is described in French Patents 2 583 519 and 2 529 472, all the while establishing material balances around a chemical reaction.
This invention therefore relates in particular to equipment for pretreatment of catalysts and/or for catalytic testing that makes it possible to draw up the material balance of a chemical reaction and therefore to evaluate the transformation of mixtures of liquid and gaseous products, in the presence of very small amounts of solid catalyst, in particular in granular or divided form, under operating conditions (reaction temperature, pressure, time of contact) of industrial use.